The electrical activity of various organs, such as the heart or brain, can be monitored, and this electrical activity can be analyzed to look for patterns that may assist in diagnosing various conditions. For example, the electrical activity of the heart can be monitored to track various aspects of the functioning of the heart. Given the volume conductivity of the body, electrodes on the body surface or beneath the skin can display potential differences related to this activity. Anomalous electrical activity can be indicative of disease states or other physiological conditions ranging from benign to fatal.
Cardiac monitoring devices can sense the cardiac electrical activity of a living being and identify heart beats. Frequently, identification of heart beats is performed by identifying various portions of the cardiac cycle as can be seen in an electrocardiogram (ECG). Various identifiers, such as P, Q, R, S and T, are typically assigned to various deflections in the ECG signal. Many techniques have been developed for analyzing ECG signals, but further improvements are desirable.